Symbolic systems are fundamental to the way we understand some of the most basic domains of human experience, including time, number, and language. The P.I. has been engaged in cross-cultural research aimed at describing how variations in symbol systems affect cognitive development. This proposal describes a program of further training in the U.S. & China which will provide the P.I. with direct experience in how children in two quite different cultures master symbolic systems, and a complementary program to develop theoretical and computational models of symbolic development. Understanding how symbolic systems affect cognition is a model cognitive science question. Answering it requires a combination of experimental and computational work. The bulk of the experimental program described here has been recently funded. This proposal has two new components. 1) The funded project will be extended by including a modelling component, in which connectionist modelling will be used to develop models of symbolic development in Chinese and U.S. children. Such modelling provides a method of exploring effects of the structure of symbol systems independent of other cross-cultural differences. A promising preliminary model of numerical development is described. This model will be extended to incorporate additional phenomena and the approach will be applied to calendar time and written language. Additional empirical studies will test and refine the models. 2) This project will provide the P.I. with an opportunity to learn a Chinese perspective on early reading and mathematics, observe children in classroom settings, and participate on the scene in developing symbolic competence tasks. This work requires the P.I. to spend significant amounts of time in China during the academic year; the current proposal will make this possible. The additional time in China will also permit the P.I. to participate in training Chinese psychologists, and the proposal will incorporate a year-long visit by a Chinese colleague to the U.S. These exchanges should help in broadening the perspectives of the psychological research community in both countries. For each of the domains of number, calendar time, and written language, developmental comparisons between U.S. and Chinese children provide a promising method for understanding the role that symbolic structure plays in cognitive development. Understanding the developmental consequences of particular symbol systems is obviously-important to determining how such cultural tools affect development. It will also permit us to distinguish general developmental problems from obstacles to learning that are contingent upon a culturally-specific way of organizing and representing bodies of knowledge.